Fuel injection pumps



March 1957 (3. F. HIGH .ETAL 2, 8

FUEL INJECTION FUMPS Filed Nov. 16 1951 INVENTOR CARL fiHlcH-gi RODERTK. WELD) United States Patent FUEL INJECTION PUMPS Carl F. High andRobert K. Weldy, Detroit, Mich, as- .signors to American Bosch ArmaCorporation, a corporation of New York Application November 16, 1951,Serial No. 256,642

Claims. c1. 103-2).

This invention relates to fuel injection apparatus and has particularreference to a new and improved combined fuel injection pump anddistributor which is relatively simple and economical and efficient inoperation.

An object of the invention is to provide new and improved drive meansfor the fuel distributor, fuel supply pump and fuel injection pump offuel injection apparatus of the type set forth.

Another object of the invention is to provide new and improved fuelmetering means for fuel injection apparatus of the type set forth.

Another object is to provide new and improved means for adjusting themaximum fuel quantity of such a fuel injection pump.

' Other objects and advantages of the invention will be apparent fromthe following description taken in connection with the accompanyingdrawings. It will be understood that changes may be made in the detailsof construct'ion and arrangement of parts without departing from thescope of the invention as set forth in the accompanying claims.

Referring to the drawings, the figure is a longitudinal sectional viewof a fuel injection pump embodying the invention.

Referring more particularly to the drawing, the body part 1 is bolted tothe flange 2 at four corners by cap screws (not shown).

The shaft 3 terminates in a spllned portion 4 which drives a rotatablecam member 5. This member has six lift surfaces 6 or lobes radially ofthe leftward facing annular face and generally triangular in transversecross section. These coact with six similarly formed lifts on stationarycam member 7 to cause member 5 to have six quick lifts per revolution ofthe shaft with a dwell of member 5 in its unlifted position betweenstrokes;

The cam.7 is hold against a shoulder in 1 by two block nuts 8 fastenedby cap screws 9. l 1

A bushing 10 is slidable axially in cam 7 to limit the retraction of cam5 which limits the displacement of pumping plungers (later toappear) forpurposes of maximum fuel quantity control. The position of sleeve 10 incam 7 is adjustable by an eccentric dog point 11 on the screw 12 whichmay be locked by nut 13.

A fuel transfer pump plunger 14 is internally splinedto slide on thesplines 4 and be rotatably driven thereby. Plunger 14 is reciprocable inan enlarged portion of the axial bore through sleeve member 15. The topface of plunger 14 is formed by a plug 16 pressed in 14. Plug 16 has atransverse slot for drivingly rotating injection plunger 17 and a tangfor engaging a coacting slot in the splined end 4 of shaft 3. A suitablespring 18 returns plunger 14 rotating therewith, its thrust beingreacted through a two plate radial annular plain thrust bearing to theright of the spring.

To insure that unavoidable inequalities in the height of the several camlifts 6 on members 5 and 7 will not cause eccentric forces to be appliedto plunger 14 by cam mem- 2,784,670 Patented Mar. 12, 1957 ber 5, theabutting surfaces of these are respectively made of spherical and planeconformation and the fit of member 5 on the splines 4 is suflicientlyloose to allow articulae tion between members 5 and 14.

Plunger 14 is formed with one groove 18a along an element of its surfacefor each of the six equally spaced lifts of the cam. On the outward orfilling stroke only of plunger 14, three of these equally spaced groovesregister with three equally spaced supply ports 19 which traverse thewall of sleeve 15 and are constantly in communication with a transversefuel supply conduit. 20. On the inward or delivery stroke only, two ofthe grooves 19 register with two equally spaced delivery ports 21 which.

are in constant communication with delivery passage 22.

only in communication. Excess fuel which enters passage 22 may beby-passed back to the fuel supply tank- (not shown) via a spring loadedworking pressure relief valve indicated at 23. The pressure relief valve23, though of 'ball construction differs from conventional pressurerelief valves in that the ball acts as a spring pressed piston in aclosely surrounding bore at all pressures below the maximum or relievingpressure. When relieving pressure is reached the ball moves outwardlyinto an enlarged portion of the bore to permit fuel to by-pass the ball.This construction causes the valve 23 to have a dual function as aspring pressed accumulator and a relief valve. Its to be noted that theaccumulator function is necessary as port 21 is closed during thefilling stroke of plunger 14 and it is during this movement that plunger17 executes its filling movement as will presently appear.

The fuel to be injected is transmitted .from passage 22 to chamber 25via drilled passage 24. During the filling movement of plunger 14 fuelunder pressure of the accumulator 23 may pass "through port 26 subjectto the variable restriction which may be imposed by the sliding sleeve27 which performs a throttling or metering function responsive to thegovernor mechanism later tobe described.

In Patent No. 2,361,399, to High is shown a rotating pump plunger withsimilarmeans to those included in plunger 14 for communicating with asingle suction passage during a filling stroke and a single dischargepassage.

during a discharge stroke. l

The injection and distributing plunger 17 ismovedinits expulsiondirection by abutment of its end} against plug 16 of fuel transfer pumpplunger 14.

Also a rotating and reciprocating pump plunger for delivering meteredquantities of fuel successively into a plurality of conduits leadingrespectively to a plurality-of engine cylinders is shown in Highapplication, SerialNo.

546,161 and also in said Patent No. 2,361,399.

the injection pump is closed by the plug 28.

,The governor mechanism includes much that is? con: 1 ventional.Governor weights 29 cause movement of a.

lever arm 30 against the force of a spring 31 which may be varied by aspeed control lever and cross shaft assembly 32 including a maximumspring tension limiting screw and its lock nut. This assembly may bemoved by speed control arm 33. A drag link 34 connects arm 30 to anotherarm 35 at the upper end of an o-scillable pin 36 having an eccentricallyformed lower end engaging throttle sleeve member 27 to move the latterfor control of the quantity of fuel to be admitted through port 26.

As plunger 17 rotates one of six (only one shown) equally spaced ports37 contained in a transverse plane therein registers with port' 26'during each filling period. During eaclr of the expulsion strokes asingle port38" in the plunger registers with one of six equally spaceddelivery ports 39 which communicate respectively with drilled passages4'0'leading' to tapped conduit connections 41 by which, conduits leadingto the respective engine cylinders maybe 'secured.

A suitable hub and retaining flange is mounted onv the outer end ofshaft 3, for supporting a driving gear or sprocket.

From the foregoing it will be seen that we have provided'simpleefiicient and: economical means for obtaining all ofthe' objectsand advantages of the invention.

We claim:

1. In a device ofthe' character described, a shaft, a pumping anddistributing member axially aligned with said shaft, a cam-memberadaptedto be rotated by said shaft; a stationary cam member, said first cammember andsaid stationary cam member having lift portions adapted toengage and effect'movement of said first cam member-,and abushing: insaid stationary cam member, said bushingbeing axially movable in saidstationary cam' member" and adapted to engage said movable cam to limitthe retraction of said first cam member and thereby limit the movementof said pumping and distributing member; for controlling the maximumfuel quantity delivered by thepump, and means for adjusting saidbushing-to thereby adjust said maximum fuel quantity, said meanscomprising a screw member having an eccentric portion and means forlocking said screw member in adjusted position.

2. In a device of*thecharacter described, a shaft, a pumping anddistributing member axially aligned with said shaft, a cam memberadapted to be rotated by said shaft, a stationary cam member, said firstcam member and said stationary cam member having lift portionsadapted-to engage and effect movement of said first cam member, andabushing in said stationary cam member, said bushing being axiallymovable in said stationary cam member and adapted to engage said movablecam to limit the retraction ofsaid'first cam member and therebylimit'the movementof said pumping and distributing member forcontrolling the maximum fuel quantity delivered by the pump, and meansfor adjusting said bushing-to thereby adjust said maximum fuel quantityincluding a screw-having an eccentric point with said eccentric pointengaging said bushing for axial'adjustment of said bushing and means forlocking said screw in adjusted position.

3'. In a device of the character described, a shaft and a fuel pumpingand distributing memberin axial alignment, said". shaft being adapted toeffect rotation and reciprocation of said pumping and distributingmember, an operative connection between said shaft and said pumpingand'distributing member, a cam member operatively connected to saidshaft and adapted to be rotated thereby anda stationary cam membersurrounding said shaft adjacentsaid' movable cam member, said movablecam member and said stationary cam member having cooperative liftportions for effecting reciprocation of said pumping and distributingmember, a bushing surrounding said shaft member, and an adjusting memberextending-through said stationary cam member and engaging saidbushing-member for effecting axial movement 4 of said bushing member,said bushing member engaging said" movable cam member to" limit theretraction of said movable cam and thereby limit the movement of saidpumping and distributing member and thereby limit the displacement ofthe pumping member for controlling the maximum fuel quantity deliveredby the pump.

4. In a device of the character described, a shaft, a pumping anddistributing. member axially aligned with said shaft, a cam memberadaptedto' be rotated by said shaft,. astationary cam member, said.first cam member and said stationary cam member having lift portionsadapted to engage and effect movementof said" first cam member, and abushing in said stationary cam member, said bushing being axiallymovable in said stationary cam member and adapted to engage said movablecam to limit the retraction of said first cam member and thereby limitthe movement of said pumping and distributing member for controlling;the maximum fuel quantity delivered by the pump, and means foradjustingsaidbushing. to thereby adjust said maximum fuel quantityincluding a screw having an eccentric point with said eccentric pointengaging said bushing for axial adjustment of said bushing and means forlocking said screw in adjusted.

position, and a fuel supply pump operatively connected to said shaftand" interposed between said shaft and said pumping and distributingmember.

5. In a device of the character described, a shaft, a pumping anddistributing member axially aligned with said shaft, a cam memberadapted to be rotated by said shaft, a stationary cam member, said firstcam member and said stationary cam member having lift portions adaptedto engage and effect movement of said first cam member, and a bushing insaid stationary cam member, said bushing being axially movable in saidstationary cam member and'adapted'to engage'said movable cam to limitthe retraction of said" first cam member and thereby limit the movementof said pumping and distributing member for controlling the maximum fuelquantity delivered by the pump, and means for adjusting said bushing tothereby adjust said maximum fuel quantity including a screw having aneccentric point with said eccentric point en:

gaging said bushing for axial adjustment of said' bushing and means forlocking said screw in adjusted position, a sleeve'for controlling thedelivery of fuel by said pumping plunger and means for effectingadjustment of said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS

